Cetomimus compunctus

Common Name

Smallmouthed Whalefish

Year Described

Abe, Marumo & Kawaguchi, 1965


Dorsal Fin: 19
Anal Fin: 19
Pectoral Fin: 23-24
Lateral Line Pores: 24-26
Gill Arches: 3.5
Vertebrae: 33+20 = 52 total

Genus diagnosis after Paxton (1989) for females:

Upper jaw length 21% SL. Predorsal Length 60% SL. Body rather elongated with a large mouth (smaller relatively than other genus members). Snout rounded. Eye tiny. Nasal organ small. Jaws slightly concave. Free gill arches number three with a short slit behind the fourth. Gill tooth plates contiguous. Lateral line conspicuous with large round pores inside a channel with raised rim. No vertical rows of papillae on lateral line. Small dermal flaps present on lateral pores. Lateral line system continues onto head as a series of pores and sensory openings. Additional pores on lower jaw and snout. Jaw teeth tiny in several irregular, diagonal rows. Vomerine tooth patch round or oval. Dorsal and anal fins located far back on body, with bases slightly elevated. Cavernous tissue located around the anus and anal fin base, around anterior dorsal base, and on both lower and upper caudal peduncle around midline. Caudal fin with less than 17 principle rays. Pelvic fin absent. Pectoral fin small and inserted low on body. Body flabby and scaleless except for large, diagnostic scales associated with the lateral line canals.

Males and juveniles unknown.


Preserved specimens are dark brown with darker pigment on lateral pores and belly and lighter pigment on the lower head and gill region. Fresh specimens said to be red-brown.


Type specimen measured 142mm SL. Recorded to 160mm SL.


Taken in midwater between the 1000-1800m.


Described from the northwestern Pacific off Japan but Paxton et al. (2016) cites eight records globally with specimens known from the tropical eastern Atlantic and the western South Atlantic.


Abe, T., R. Marumo & K. Kawaguchi. 1965. Description of a new cetomimid fish from Suruga Bay. Japanese Journal of Ichthyology v. 12 (nos 3-6): 57-63.

Maul, G.E. 1969. On the genus Cetomimus (Cetomimidae) with the description of a new species. Bocagiana. Museu Municipal do Funchal (História Natural) No. 18: 1-12.

Paxton, J.R. 1989. Synopsis of the whalefishes (family Cetomimidae) with descriptions of four new genera. Records of the Australian Museum v. 41: 135-206.

Paxton, J.R., T. Trnski & G.D. Johnson. 2016. Cetomimidae (Pp. 2173-2181). In: Carpenter & De Angelis (eds.). 2016. The living marine resources of the Eastern Central Atlantic. vol. 3.

Other Notes

The exact western Atlantic record of this species from the western South Atlantic appears to be unpublished (?), but it is included citing Paxton et al. (2016). The illustration included for this species in FAO is identical to the one in Paxton (1989), but it has 20 lateral pores and matches the description of Cetomimus hempeli better than C. compunctus which has a noticeably shorter head and longer dorsal/anal fin bases than any other Cetomimus.